Learning Forum

[kemalb123]

Hi everyone,

I am doing a non linear buckling analysis on ansys workbench. I have a problem in the finite element modeler. Here is my project schematic.

After the eigenvalue bukling analysis completed, I clicked the tools button and the write INPUT File. Then I erase all the content of it and  I put these command in the input file for the mechanical apdl :

/prep7

UPGEOM,1,1,1,file,rst

cdwrite,db,file,cdb

Then, I load the input file to the Mechanical APDL. After that, When ? open the finite element modeler, ? see this:

As you see in the picture which is above, I cant get any geometry. I don't know where is the fault. Can you help me about this?

Thank you so much.

[jj77]

The FE modeler does not work (I think one can see the red cross indicating an error).

 

Instead of linking the FE modeler to mech. apdl, just set it up as standalone (no link to mech. apdl). In order then to generate/get the mesh into the fea modeler, right click on it, go to add input mesh, and browse to the .cdb file manually.

That should work .

 

[kemalb123]

I tried it. Unfortunately, it didn't work. I can take the geometry directly from the static structural. Here is the picture of it.

It works like that. But ? need the deformed shape. Also ? tried this one.

It worked. But ? can't get the geometry from the MAPDL.

[jj77]

Ok here is the work flow (numbers relate to image below) because it is confusing (you do not need to get any geom, it is the deformed mesh we need, that is finally imported to a linear static, which will then make/get faces from the FE modeler data).

 

1. Run linear static, couple (2) to linear buckling.

3. Use the Mech Apdl (add the input file, with commands you mentioned UPGEOM) using the results from the linear buckling, and using upgeom to generate the deformed mesh, that is written finally to the cdb file. Make sure that your file folders are the correct ones.

 

4. Open this cdb file in the FE modeler (manually as explained).

5. Finally link the FE modeler to the static analysis (nonlinear buckling). See image below. That works.

[kemalb123]

Sir, I did your work flow step by step correctly. But I got the error again. In the picture, Messages section, number 5, it says "The model doesn't contain any valid components to create a geometry. Valid components are composed of shell elements or faces of solid elements." what does it mean ? Should I attain an element in Mech APDL ? I think that I have problems with the Mech APDL.

I do right click on the analysis tab which is under the  Mech APDL, and click on the Edit in Mech APDL, I got that warning. Is it normal ?

Columnbuckling-INP.inp is the file which contains UPGEOM command. It is also shown in the picture shown belov.

[jj77]

From the error message ("The model doesn't contain any valid components to create a geometry...") it looks like you do not have a shell mesh or a brick 3D mesh (it would not be able to create geometry say from beam elements), so not sure how your mesh looks like, but that is the problem.

[kemalb123]

I'm so thankful to you for your help and patience. On the static structural, I opened the model then I insert a command box under the  surface body. Then added the element type command. Finally it worked.

[jj77]

good that you managed to sort it out.

 

 

[kemalb123]

I have one more question. I wanted to find 4 mode shapes for linear buckling analysis. In the non-linear buckling analysis, which mode shape used by ansys workbench?

[James02dai]

Hi, for the static structural,what command did you insert under the surface body? Can anyone give an example? I was facing the same problem ("The model doesn't contain any valid components to create a geometry...")

[kemalb123]

Hi,

the reason for the problem (The model doesn't contain any valid components to create a geometry...) is the path file of your project. If you save it on your desktop, documents etc. it creates problems. Firstly, you check your project path file. Use any folder in you C:or driver.

For the analysis, this video can help you. It defines all the process and commands : https://www.youtube.com/watch?v=aBmnTel4msc&t=2s 

[James02dai]

Hi,kemalb123, I added input file in apdl, and it works fine. When I linked it to finite element modeler, then updated it, it pops the error. It said the finite element modeler is fail to update.

[BillProfis]

Hi, everyone. I have a little trouble proceeding from Eigenvalue to Mech APDL. It show me the following message. What is going wrong?

[BillProfis]

It says " update failed for the Analysis component in Mech APDL. The solver failed with a non-zero exit code  of : 1" . I have entered the upgeom1.inp  file before i update the APDL. Any help plz, i am very new to this programm. Also the geometry as following :